Watercraft

ABSTRACT

A WATERCRAFT HAVING A PAIR OF SUBSTANTIALLY PARALLEL, LONGITUDINALLY ARRANGED, RECESSES OR TUNNELS POSITIONED BELOW THE WATERLINE IN THE AFTER PORTION OF ITS HULL AND A SUITABLY DRIVEN PROPELLER LOCATED WITHIN EACH RECESS AND MOUNTED FOR PIVOTING AROUND A VERTICAL AXIS. FLAPS CLOSE THE AFTER END OF SAID RECESSES WHEN THE CRAFT IS OPERATING   IN REVERSE AND THE ENGINE IS PEREFERABLY PLACED FORWARDLY OF THE FORWARD END OF SAID RECESSES.

March 23, 1971 J. BECKER 3,572,281

WATERCRAFT Filed Dec. 23, 1968 3 Sheets-Sheet 1 //2 van far Jon! hiker Alla/ways March 23, 1971 J. BECKER WATERCRAFT Filed Dec. 23, 1968 SSheets-Sheet 2 v Alla/00y! March 23; 1971 J. BECKER 3,572,281

WATERCRAFT Filed Dec. 23', 1968 3 Sheets-Sheet 8 60 51 i 26 53 f6 Z:/9 j: i

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United States Patent US. Cl. 115-37 12 Claims ABSTRACT OF THE DISCLOSURE A watercraft having a pair of substantially parallel, longitudinally arranged, recesses or tunnels positioned below the waterline in the after portion of its hull and a suitably driven propeller located within each recess and mounted for pivoting around a vertical axis. Flaps close the after end of said recesses when the craft is operating in reverse and the engine is preferably'placed forwardly of the forward end of said recesses.

This invention relates to a watercraft which is driven by two propellers which for the purpose of steering the craft are pivotable about an approximately vertical axis, preferably through at least 180.

The purpose of the invention is to produce a craft with little draft which in relationship to its power is of a light weight and easily maneuverable. The craft is intended to be able to move through waters which are difiicult for conventional craft to navigate. It is arranged for easy transport by vehicles and unloaded from the vehicle to the water in such a manner that the sensitive parts of the craft, particularly the propellers, will not be damaged. The craft will rest securely on the vehicle and will not tip when unloaded into the water. Even though a high drive capacity is provided in a small and light body, the craft will still ride easily in the water, independent of the power developed for the drive. The helmsman can maneuver the craft in spite of the high drive power with simple means, in a safe manner and with use of only a little force. The craft, even if it has only a small draft, will, if desired, maintain its full power output.

To attain these purposes, the invention provides that the portion of the hull carrying the propellers is recessed upwardly in such a manner that the lower edge of the propeller does not extend substantially underneath the keel line of the hull. Preferably, the watercraft is so con structed that the portion of the hull carrying the propellers is recessed upwardly in such a manner that the lower edge of the propellers is actually positioned higher than the keel line of the craft. Thus, the propellers are protected against the ground during transport on land and also from running onto the bottom of a water body during use.

In order to prevent the propellers from sucking air during a situation of minimum draft of the watercraft and thus to lose output, apparatus of the invention is constructed in such a manner that the portion of the hull which carries the propellers is constructed as an inverted trough at least partially surrounding the propellers, in such a manner that the lateral walls of the recess or the recesses extend underneath the water surface. A loss of power through interference of the propellers with each other is avoided or eased in such a manner according to the invention that the propellers are each received in one recess which are separated at least partially through a center part of the craft hull.

The invention further provides that the recesses which are open toward one narrow side of the craft, for example, the stern, are closable by one or several flaps "ice which, in one direction of movement of the craft, are arranged to prevent access of air to the propellers and, in the other direction of movement of the craft, are released to avoid causing resistance to such movement. Thus, the craft also obtains, in spite of its small draft and the elevated position of the propellers, a high power output during reverse movement because the drawing in of air is avoided during such reverse movement. If the propellers are arranged also on the bow or on both the stern and bow, then the flaps of the invention are to be provided also at the bow end of the recesses.

The craft is provided according to the invention with two keels so that it rests securely during a transport on land.

Considering the purpose of the invention that the watercraft is to be very sturdy because it is intended also for use, for example, as a work craft (hauling, towing) and must be transportable on land and for this purpose must be able to be pulled out of the water and be returned into the water, the body of the craft is constructed so that principal parts of the sides are curved. Preferably, according to the invention, all walls of the craft hull are constructed curvedly.

The craft of the invention is further constructed in such a manner that the propellers, for the purpose of changing direction, are pivotable through at least 360'. This type of construction, in consideration of the abovediscussed purpose, becomes possible or meaningful only through the inventive construction of the craft hull.

Also, the design of the craft of the invention, especially the hull thereof, cooperates with the opposite rotation of the propellers to attain the objectives of the invention.

The desired high output can be obtained in a flat running boat or ship according to the invention by installing the driving shafts extending underneath the water surface for rotation in opposite directions.

An important characteristic of the invention is that the motor driving the propellers is arranged in the part of the craft hull which is not provided with the recesses receiving the propellers. Thus, the craft lies stable both in and out of the water.

The boat of the invention further is constructed in such a manner that the propellers are driven by the motor through transfer elements and through power dividing gearing and also through driving shafts extending underneath the water level. The vibration characteristics of a boat constructed according to the invention are improved by supporting the transfer elements approximately in the center thereof by a bearing located on the craft hull.

The form of the craft of the invention permits a further desirable feature, namely, that the propellers are driven through a reverse gearing. Even though the craft lies very flat in the water, the invention permits a high speed rotation of the propellers, that is at a high effectiveness of the propellers (because the sucking in of air is avoided).

Further characteristics and advantages of the invention will be understood from the description and the drawings.

The invention is discussed in connection with the drawings in which:

FIG. 1 is a longitudinal cross-sectional view of the part of a watercraft of the invention which is important to the invention.

FIG. 2 is a schematical top view of the elements for transmitting the power from the motor to the propellers through a distributor gear.

FIG. 3 is a schematic view bent in a plane of the power path (gearing) of FIG. 2 without elements for a speed transmission and/or speed reduction. Also, a possible clutch mechanism or clutch mechanisms are not illustrated.

FIG. 4 illustrates the hull of the watercraft of the invention seen from the stern.

FIG. schematically illustrates one form of reverse gearing of the invention.

FIG. 1 is a longitudinal cross-sectional view of a portion of the hull of a watercraft of the invention and illustrates the elements which are important to the invention. A motor 2 is supported in the hull 1 by known means which are not illustrated. A known clutch device 3 is connected to the motor 2. The means for operating the clutch are known and are therefore not illustrated. A connecting shaft, for example, a drive shaft 4, is connected to the output shaft of the clutch device. The free end of the drive shaft 4 is connected to a bearing device 5 which is secured in a bulkhead 6- of the craft, extends through said bulkhead and is sealed. The bearing device substantially comprises a transfer shaft 7 which is supported in a housing and is sealed. The housing is secured to the bulkhead. The transfer shaft 7 is provided with a connecting flange on both sides of the bulkhead. Said drive shaft 4 is secured to the connecting flange 8 which is provided on the side toward the motor and a second drive shaft 10 is connected to the other connecting flange 9. The free end of said second drive shaft 10 is connected to the flange 11 of a driving shaft 12 which is supported in the housing of power divider gearing 13 (as can be seen best in F-IG. 2).

Instead of the drive shaft 4, 10 and the bearing device 5 which is used as a sealing, in another construction of the watercraft a different shaft connection, for example, one single connecting shaft 14 (FIG. 3) between motor and distributor gear 13, can be provided. A bevelled driving gear 15 is in meshing engagement with a bevelled driven gear 16 which is arranged rotationally fixed on a distributor shaft 17. Said shaft 17 constitutes the driving shaft of the power divider gearing. The distributor shaft 17 is used to divide the output of the motor to the two steerable propellers 18, 19. Said distributor shaft can be put together of several pieces. One bevel gear 20, 21 is secured to each of the ends of the distributor shaft. Both bevel gears 20, 21 are supported in the above water gear housings 22, 23. The last-mentioned bevel gears each act through further bevel gears 24, 25, which also are supported in the gear housings 22, 23, respectively, to drive the driving shafts 27, 28. These latter are substantially perpendicular to the water level 26. A suitable, not illustrated, shifting clutch can be provided in a suitable place between the power divider gearing 13 and the driving shafts 27, 28. Said shifting clutches can replace the clutch 3 or can be provided in addition to the clutch 3.

The driving shafts 27, 28, transfer the drive output onto the underwater portion of the gearing of the steerable propeller which gearing is arranged in the underwater housing 29', 30'. The propellers 31, G2 are supported in said underwater housing by means of propeller shafts 33, 34. The underwater housings 29, 30 are pivotably supported relative to the above-water housings 22, 23. The support can be done by means of telescoped tubes. It is very advantageous to support the one housing by means of a faceplate in the other housing. The watercraft is steered by pivoting the underwater housing. The steering movement is transmitted from a steering wheel, which is not illustrated, through suitable lines schematically indicated in dash-dotted lines 35, 36, in any conventional mechanical, hydraulic, pneumatic or electrical manner.

One bevel gear 37, 38 is secured to each lower end of the driving shafts for driving the propeller shafts 33, 34. The bevel gears are each in meshing engagement with one further bevel gear 39, 40' which are positioned on the propeller shaft and drive same.

The bevel gears 15, 16; 20, 24; 21, 25 are arranged in such a manner that the driving shafts 27, 28 rotate in opposite directions which balances out the reaction moments transmitted to the control. The bevel gears 37,

4 39; 38, 40 are arranged in such a manner that the propeller shafts 33, 34 rotate in opposite directions so that the reaction moments transmitted to the craft hull are balanced. The directions of rotation are indicated by the arrow 46 to 47.

FIG. 4 illustrates the hull of the craft seen from the stern. According to the purpose of the invention the craft must be quickly loadable and transportable on a 'vehicle and must be capable of rapid launching. The craft hull is for this purpose provided with two keels, 48, 49. The propellers are arranged relative to the keels in such a manner that their radius of action 50' does not intersect the keel line 51, 51'. The craft hull has recesses 52, 53 in the area of the steerable propellers 18, 19, so that water which is being drawn in by the propellers can flow towards the propellers without appreciable resistance. The sidewalls 54, 55 extend underneath the water level 26 and prevent the propellers from sucking in air. Thus, the propellers are on one side protected during transport and against running aground and on the other side a high effectiveness of the propellers is assured.

The walls 56, 57, 58, 59, and of course the walls of the recesses-are of a curved shape so that the body receives a high rigidity and thus meets the requirements of transportability and resistance in case of collisions. The recesses are open to the stern. The recesses are closed by flaps 61, 62 so that the propeller in operating the craft in reverse cannot suck in air. The flaps are suspended by means of hinges or the like in such a manner that the fiapslike nonreturn flaps-can close the recesses during reverse operation and during forward operation can open to minimize driving resistance.

The propellers are additionally protected with laterally arranged rods 63, 64.

FIG. 5 illustrates a combination of the power divider gearing 13 with a turning gear. This above-mentioned driving shaft 12. is supported in the gear housing 65 which can also be constructed of multiple parts. The driving shaft has a connecting flange 11' at its outer end and is provided with a bevel gear 66 at its inner end. This bevel gear is in meshing engagement with two oppositely positioned bevel gears 67, 68 which are supported in the gear housing. The distributor shaft 17 is supported coaxially to the last-mentioned bevel gears so that torque is not directly transmitted from the bevel gears to the distributor shaft. Clutch cones 69, 70 are fixed to the oppositely positioned bevel gear, said clutch cones having a plurality of recesses 71, 72 in their periphery. The distributor shaft 17' is provided with clutch splines on which a. clutch body 74 is longitudinally movably sup ported. The clutch body has on both sides an external toothing 75, 76. Clutch plates are inserted in a known manner between the clutch cones 69, 70 and the clutch body 74, some of said clutch plates alternately being in constant engagement with the recesses 71, 72 of the clutch cones (outer clutch plates 77) and the clutch plates positioned therebetween engaging the clutch teeth 75, 76 (inner clutch plates 78). The clutch body is provided with an annular groove 79 between the external teeth at the periphery of a collar which is used as a support for the plates. A control shaft 80 is supported in the gear housing, a control lever 81 being secured to the outer end of said control shaft. The control shaft is provided with an eccentrically located pin 82 at its inner end, said pin engaging the annular groove. As the control lever is moved, three conditions can occur. If as in FIG. 5, the eccentrically positioned pin presses the clutch member to the left, then the distributor shaft is driven in one direction of rotation through the elements 12', 66, 68, 69, 77, 78, 74. If the control lever is moved in the other direction, then the distributor shaft is driven in a corresponding manner in the other direction of rotation. Idling occurs in the center position. FIG. 5 illustrates only a schematic picture in order to explain the function. In order not to confuse the picture, it was not developed in detail. Thus, in practice, for example, usually the eccentrically positioned pin 82 is not sufficient but it must be provided with a bearing, preferably a roller bearing, in order to keep the friciton small between the pin and the walls of the annular groove. Also, the construction of the turning gear as a plate clutch is only an example. This structure can be very advantageous because it permits a shifting during operation. Thus, the main clutch 3 may not be needed. However, it is also possible to provide jaw clutches or any other conventional shifting means as desired.

FIGS. 1 to 5 are limited to illustrations which are necessary in order to understand the invention. Lubricating and servicing elements and devices for the energy supply and for cooling of the motor are not illustrated.

The gearing schematics illustrate the elements only as they must be understood for the direction of rotation. Specific ratio-changing systems have not been illustrated because they are not a part of the invention. The moments of rotation are balanced according to the invention. Stabilizers 83, 84 can also be provided on the underwater portions of the steerable propellers to absorb residual moments.

The example illustrates a craft with two propellers arranged at the stern. The propellers can also be arranged at the bow without changing the invention. It can be particularly advantageous for work craft to provide according to the invention, for example, two steerable propellers at each of the stern and the bow.

The watercraft of the invention is easily maneuverable and can therefore run well on shallow and winding waterways. It is small and of a light weight but has a high power output and can therefore be transported on land vehicles and can be easily unloaded into the water and can be moved easily out of the water. The shape of the craft hull is chosen so that the body can resist the stresses of a transport by land and collisions whereby the propellers are also arranged in a well protected manner with out affecting their effectiveness. The moments of rotation are received by the arrangement of the invention in such a manner that in spite of the high power output and the small size of the craft, the craft has a good attitude in the Water and is easily steerable. The craft of the invention is suitable as a work boat, for example, for hauling and towing.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A twin-screw power-driven watercraft, comprising in combination:

wall means defining a pair of substantially parallel,

channel-like troughs in the bottom portion of said watercraft extending longitudinally of said Watercraft and located adjacent at least one longitudinal end of said bottom portion;

at least two propeller housings each having a propeller rotatably mounted thereto, one of said propellers being arranged in each of said troughs and proportioned with respect thereto so that said propellers are at least substantially above the keel line of said watercraft;

means supporting said propeller 'housings for pivotal movement around separate vertical axes;

said wall means including a downwardly extending intermediate wall portion disposed laterally between said propellers and extending longitudinally both forwardly and rearwardly relative to the propellers, said intermediate wall portion extending downwardly a substantial distance below the upper most point of said propellers for at least partially isolating the propellers from one another in all positions of use thereof to thereby minimize interference of the water driven by the propellers; and

power means for driving said propellers.

2. A watercraft according to claim 1, wherein said bottom portion includes elongated and upright sidewall means adjacent laterally opposite sides of said wall means and extending parallel to the longitudinal axis of said watercraft, said elongated and upright sidewall means projecting away from said bottom portion below the waterline of said watercraft to at least said keel line to prevent communication between said troughs and the laterally external sides of said watercraft except by way of around the bottom edges of said elongated and upright sidewall means.

3. A watercraft according to claim 2, wherein said elongated wall means extends along said opposite sides of said pair of troughs at least at the laterally adjacent sides of said propellers.

4. A Watercraft according to claim 2, wherein said bottom portion opposite said one longitudinal end has a pair of laterally spaced keels.

5. A watercraft according to claim 4, wherein each of said keels is longitudinally aligned with the central axes of one of said troughs.

6. A watercraft according to claim 5, wherein all of the walls of said bottom portion are arched.

7. A watercraft according to claim 2, including flap means adjacent at least one end of said watercraft and adapted to move across said one end of each of said troughs to prevent said propellers from sucking air into said troughs when said watercraft is moving in one direction, said flap means being further adapted to move away from said one end of each of said troughs when said watercraft is moving in a direction opposite said one direction.

8. A watercraft according to claim 1, wherein said power means includes an engine and driven shaft means adapted to drivingly interconnect the output of said engine to said propellers, said engine being mounted internally of said watercraft at a location longitudinally spaced from the end of said watercraft having said troughs in said bottom portion.

9. A watercraft according to claim 1, wherein said propeller housings are supported for pivotal movement through at least 360 degrees.

10. A watercraft according to claim 1, including reversing gear means adapted to drive the propellers in either direction of rotation about the axes of rotation thereof.

11. A watercraft according to claim 10, wherein said reversing gear means comprises a bevel drive gear and two bevel driven gears coaxially arranged on a driven shaft, said two bevel driven gears being in continuous meshing engagement with the said bevel drive gear, said reversing gear means further comprising clutch means adaptable to selectively connect alternate ones of said bevel driven gears to said driven shaft.

12. A watercraft according to claim 1, wherein said inter-mediate wall portion extends downwardly to at least substantially the elevation of the rotational axes of the propellers.

References Cited UNITED STATES PATENTS 2,336,987 12/1943 Garber et al. 11456 2,936,730 5/1960 Patty 115-37 FOREIGN PATENTS 960,907 3/1954 Germany 1l5-35 TRYGVE M. BIJIX, Primary Examiner U.S. Cl. X.R. 115-35 

